Modern vehicles are increasingly being sold with backup or reverse facing cameras to allow a driver to view what is behind the vehicle. This is especially true for vehicles that are used to pull a trailer, where the driver's view may be blocked.
Some rear facing cameras may be wired, such that communication between the camera and the vehicle is done through a wired connection. Alternatively, some cameras may be wireless, and may transmit images and video to the vehicle via one or more wireless communication protocols.